<?php
/**
 * Smarty plugin
 *
 * @package    Smarty
 * @subpackage PluginsFilter
 */

/**
 * Smarty trimwhitespace outputfilter plugin
 *
 * Trim unnecessary whitespace from HTML markup.
 *
 * @author   Rodney Rehm
 *
 * @param string                   $source input string
 * @param Smarty_Internal_Template $smarty Smarty object
 *
 * @return string filtered output
 * @todo     substr_replace() is not overloaded by mbstring.func_overload - so this function might fail!
 */
function smarty_outputfilter_trimwhitespace($source, Smarty_Internal_Template $smarty) {
	$store = array();
	$_store = 0;
	$_offset = 0;

	// Unify Line-Breaks to \n
	$source = preg_replace("/\015\012|\015|\012/", "\n", $source);

	// capture Internet Explorer Conditional Comments
	if (preg_match_all('#<!--\[[^\]]+\]>.*?<!\[[^\]]+\]-->#is', $source, $matches, PREG_OFFSET_CAPTURE | PREG_SET_ORDER))
	{
		foreach ($matches as $match)
		{
			$store[] = $match[0][0];
			$_length = strlen($match[0][0]);
			$replace = '@!@SMARTY:' . $_store . ':SMARTY@!@';
			$source = substr_replace($source, $replace, $match[0][1] - $_offset, $_length);

			$_offset += $_length - strlen($replace);
			$_store++;
		}
	}

	// Strip all HTML-Comments
	// yes, even the ones in <script> - see http://stackoverflow.com/a/808850/515124
	$source = preg_replace('#<!--.*?-->#ms', '', $source);

	// capture html elements not to be messed with
	$_offset = 0;
	if (preg_match_all('#<(script|pre|textarea)[^>]*>.*?</\\1>#is', $source, $matches, PREG_OFFSET_CAPTURE | PREG_SET_ORDER))
	{
		foreach ($matches as $match)
		{
			$store[] = $match[0][0];
			$_length = strlen($match[0][0]);
			$replace = '@!@SMARTY:' . $_store . ':SMARTY@!@';
			$source = substr_replace($source, $replace, $match[0][1] - $_offset, $_length);

			$_offset += $_length - strlen($replace);
			$_store++;
		}
	}

	$expressions = array(
		// replace multiple spaces between tags by a single space
		// can't remove them entirely, becaue that might break poorly implemented CSS display:inline-block elements
		'#(:SMARTY@!@|>)\s+(?=@!@SMARTY:|<)#s' => '\1 \2',
		// remove spaces between attributes (but not in attribute values!)
		'#(([a-z0-9]\s*=\s*(["\'])[^\3]*?\3)|<[a-z0-9_]+)\s+([a-z/>])#is' => '\1 \4',
		// note: for some very weird reason trim() seems to remove spaces inside attributes.
		// maybe a \0 byte or something is interfering?
		'#^\s+<#Ss' => '<',
		'#>\s+$#Ss' => '>',
	);

	$source = preg_replace(array_keys($expressions), array_values($expressions), $source);
	// note: for some very weird reason trim() seems to remove spaces inside attributes.
	// maybe a \0 byte or something is interfering?
	// $source = trim( $source );

	// capture html elements not to be messed with
	$_offset = 0;
	if (preg_match_all('#@!@SMARTY:([0-9]+):SMARTY@!@#is', $source, $matches, PREG_OFFSET_CAPTURE | PREG_SET_ORDER))
	{
		foreach ($matches as $match)
		{
			$store[] = $match[0][0];
			$_length = strlen($match[0][0]);
			$replace = array_shift($store);
			$source = substr_replace($source, $replace, $match[0][1] + $_offset, $_length);

			$_offset += strlen($replace) - $_length;
			$_store++;
		}
	}

	return $source;
}

?>
